SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7f24557031aba325b4bb0be6dc5b2df282678fe49e70e4b654d0329353485e9' 
  AND token = 'Cj+XJBuMOYiqbgxelUrDinhoih7uvKvGVRSRd2+RfBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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