SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9903808cfc0682f9375e1ccf120ae0ebd9523d0058ad02b4058c8162d8b6fdf5' 
  AND token = 'idioAafILDUBR5dYDJMivdlP0pm6+A/HNHtXIqAPlmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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