SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43c5862435d9030d36a0231eeea9aec896b37d30fc6d051d9c16cc555f42139c' 
  AND token = 'oDZMQYyvRNTPNYnQnjUZpLEOKwGuTUtT+gZNTIYWwwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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