SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1af6f09b5c0a778b11db278cf4cf44ded864fdedbfed0d17cee50feaad0fc35' 
  AND token = 'OoWYcuk3oR28owEqXrDcDekBLlzfmxCJaD+8eD9mAxs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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