SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd273258e3a4a445ebcc586e2837befddf5fa31f54f24398feeab571ef3e73e04' 
  AND token = 'sPodrFMRFxbN9zGiW54XNC7DnR40NOkE4C2x932E198=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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