SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5b82e93d61485c1b058d83f239b67feca20d2393c1b54944d5bc38d49cf9147b' 
  AND token = 'u1BYBDIHSMfXbcajKpd6q6HGp8wOWwqpgRUDp3pSXhs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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