SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '6919522a7c6d52c68592a7d209258dd18e34da6e1625dc984cc6b390dce60f41' 
  AND token = 'KEBV18dPaom/t6aeBc2+iVkpngkK20vfrUsxJg80AwM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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