SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0eba2feb663fc63b01134277ed600516c6bee523a55f664c01d35c5407da06a' 
  AND token = 'ojA1tUXpdOcvVd2QDX2raUng+ykti4Jr0/cso3oWOpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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