SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e61d674132ebf66fb0f6bdad215396b593ac8669253731a309211d03d1380466' 
  AND token = 'Gurc28EMefSM1oOYzQaWfHS6k5Ew3xjfP5aVxrV4q48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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