SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0910f6dcbcca291f97a195630a72cb6429b2631035c38385436b50696f51a0dc' 
  AND token = 'F9PJTthq55ZHdgVKAHwMtGbUA5C42ZB27XG504vDw74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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