SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bca0318f56175403db457ad4925fd331f0df38fca396a11e984fb95b66371157' 
  AND token = 'vmJULjb53cWib1DZkvfjHYJb0JWRy1uhJADRh0G7+40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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