SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89a7224ffeee16eb4cc62944b4c45215b0906ebe522c347495f78b379973354a' 
  AND token = '+VnPlfIU9/OUFkwK/9ETUBGhTgAm11rLi1fyUgGu2jw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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