SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b7fb5fc8dd0ebaf17aabf124acdcb1440aa7a0db0ecb419bcfb5ca229c5ef05' 
  AND token = 'h5QpHwOsNaTOLYpkSjccAt/21pqXndsmxAoRb6iyu7Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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