SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e53bf605b1180e078002735c36bfb21f9762374f4ce2fa606fb3da69cd06e6f' 
  AND token = 'JiW8Ypzrc1g9DAogO+KmHl+6Z6Gvr2NSljCmvH/fKJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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