SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87056986ba836a58d03cf79470929667054335ea041b03b537031913b26d8acb' 
  AND token = 'IGHvZsanBHxMEx6iQFTJ8cKzKIwGqnNsZpguZpScB/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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