SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '07dfb78612dbe0ea7694256e4bf409645b00b571ecf5db6656e92b0d1a9df705' 
  AND token = 'OsltVB5wDGojLCvQz3q4aM57UIKbZe0JyI9AZYpWF6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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