SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a20cc967463c7dbffeb16aed87b84cdf444b998285490dde3215bf243178c812' 
  AND token = 'lcQwyGooWCId9NBhDWikL4/BhUHRib51QAAKx1/5hog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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