SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63c81294fbad88cc578dd69903587b0ffe65f620c739803df31e62278f03eb94' 
  AND token = 'PVuh3iiFpVcT6fZkvX2sCLfrmrSNHRPpkQ6JxF/WNzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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