SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1927babf6d32280760fe06c429f58c4c5542f047af5c2368c2ae54f7006e3a76' 
  AND token = 'QddKBiUq1EaUnI/Tu71RUzoj/WVlp9T+2KECzYktJYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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