SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10a93c645edeede697aba8ab8b53a27ebb42623c8856a8b3bf8d2bc10503aa99' 
  AND token = '6IiPYcOcFKqcAgKBuXxQiGwHu4Urz7MglC8q2OEumv8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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