SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2a7071da5259769997e3127ef3fbe9a7bb19b00672783d59b029520980648172' 
  AND token = 'LnG03ydrnvGolVMkClhiTqNJ7OVFe5uxAPqJeQZf4WE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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