SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b911adafb89dad5075c1594b48c87e4e8904c72c76a70ebed42fad6804878739' 
  AND token = 'Lw33Ns6iiSxGcifeSHF71p8RGMKdx49uJ7/YudHD91I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}