SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfacd85943a840ee20dc45fb76e12d068614d39049dcab7e5922b3f7776e620f' 
  AND token = 'cScNDbv0/PNCsgSFEE3VADvWWEg1yAikrKa7D14pXX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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