SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f66bc72cca23285db73f19b4a7244d7f0c1c607dc906643ef479d16f188828fa' 
  AND token = 'x6sIP2FIpYCLHjNoQ528W+76L7F8sg/Iab+H6Cgfm1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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