SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c79758bbab8d39e3957072fcc4adf2f6dcb06151598a06f1b3b0141e2900ddc' 
  AND token = 'aBxE3E8ucIP8Xf0DyG7kgJfAC6wWL/SehkAYg7wUgLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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