SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee557c5c42b4c2f591d80eee035ec0aa4d52cb6b6bb0eaeecb80a9a782295376' 
  AND token = 'DzZvEPU7tJGkGveDzaUzpIkfNr5N1VttsCr2yuQbqgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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