SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e7ab0828cc7e18262c4430c5749f3579bb591f5b76e658cb5dd57648b04dff9' 
  AND token = 'L4MU8j23OkIG6OqoYqzJhm3O0Cefi9FGOa/nw10tIiM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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