SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e043fcd24d6486cf32506abc014f2a144263e94dd3eaccc5db52eadf98acbbc1' 
  AND token = 'iC589cgcO+tEjBp9+QdVdIdMRGk0YHQKTJvalY5Lpzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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