SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '636e781d3a64526d524a39ebdcbc9db56e9c19d8bcf50a8cf4c31689cfbc0a57' 
  AND token = 'se5wlq1UMF43IT7ysNo4bwvAOH64u3FIbTdWVBEVRvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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