SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '216984343235639a99b6e1d7cba86b02181624a14091dd16b0ce2400a373443f' 
  AND token = 'qJvmvdVDzeUOWd4rJ84myjIOlvHMBtp5JdX5LfrpgBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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