SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b13a759b2d55a3717450f9b55ca44879c163964b2bb4564f154a4cdad3e9a44a' 
  AND token = 'JNJ7BtJpFYYq936+LtLz6Vmz+ILrj+ul7lk4fopz6Jk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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