SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'be78eea92b3a9773dc23c4c3ed26b65003898aac9bfffd68424c44c0d666f4b4' 
  AND token = 'DnyXdDGgzV6xtEuxNTrqMkn56W/+PlSTr0YB337oOYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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