SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e34ced4795dc4566f9ad0f6e1e3481189d17d3ad06b74d1b3607a267b355523' 
  AND token = 'b7mkTWMNQnmKJH31p4SBNnfomXInLd8A325cLSIGTcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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