SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bca904b6258fed76746aee52e40db0ef759582673d60b7b20c998d4dd9b0fbee' 
  AND token = 'ZTk/IvLESAFvAW8KDyCBuyc0vCflr7kVPpsfreifqxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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