SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ceb8758a94fb2cc602304c73a1ac470d40fc0308b3847f2c88d5f88b5edbb025' 
  AND token = 'eNJ4TKlu4KD7LsSQfXsEmTqKq9JyNBc5AGZ6KIallgg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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