SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bebb785d5e01fe50d11fbca11d4c5dcf6a038202e1a5f9d159df1ab1856a515' 
  AND token = 'tVk5SciZk8C1SeTcgt/cIRJTSvbXE16EnrfHmGpny34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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