SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd1c27031524b163fec449f549a5b97746c9db41089e3d6899419d1f11190d44' 
  AND token = 'bQ88cgEiJdt/e+t+BZOv75L0zbT4qhM4jjRUJ8zswFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}