SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fe1b62dac84a169594ee1eaa122070f94426181325cc0b8ae4178fc341d07b5' 
  AND token = 'sjNPtk0kcVWhShAUfatN4g5yVPn1nN61J7szhIx/ITw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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