SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14d58c48cb295044af01887f4cf3be539400556bf07fc917d666b05100c10282' 
  AND token = 'zIar3xdUKBsVhkS3Gh06VGBVRIDJtWI+L//e1QfdvFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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