SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69f211f7ed099474bfff244114b142f4019a3161479317751894ba89144329da' 
  AND token = 'DImc8GIBgaPcSy9XkIEKovIj7JxCPsJ+b7XrJcoAfk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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