SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec097f7f78e7bdcc26e1ddf2b5c478f21259ba195164fcd14f5ae95f5f507020' 
  AND token = 'MLt8XleQFNzSF1rOO0FHVUDh4+FB5P74BdUK6UxFQ5E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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