SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1841f2525cc721ddf2a0f00d1216b855e86d63ee95e80d86b9ec5862cbfa481e' 
  AND token = 'mwmIyfpqkM5tvbwPy6YE8LQsRRVQHzSDHsGA0CIgzP4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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