SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1df6908436b9422288fc9864d1eeaaaca88a784f7bff9418dfe95f6cee6efa4' 
  AND token = '7EfGUVjRg+mPXqU/ON10tqpLbyod9Av9kRvj04KWtAA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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