SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '341be2e2fe518b7e44d7e329ff36563bcee07135d0f77e03a520a1bfd5541663' 
  AND token = 'XWOdhC0GGRIPva4zSjVfVB8ShOvoURAQ4RIqJjmM/Gc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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