SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5833efb55f0c6bbaa3e62d40db021801dcd12f8b3b3927754f48236108659eab' 
  AND token = 'OBqf2sW+VyOBMq2vn04xeWE8lBruRA6WW4gQmeTt8EU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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