SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '967e62d75403e0014ddb3278b619c8702f45233f4f25807241d5f89c73f3d496' 
  AND token = '/nosaQpgnEHqMho1HunFoiwVyyDHLmIe0piCrwhrSdc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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