SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10af51cac09416dd98a32cd69ad7961a66f8041a59f784091b572297e1555b85' 
  AND token = 'ZEzKA6gVkK4aHKkT51Hvb+qLTSaFr538PGNN2Caxlz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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