SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3cd7c6519b5d73f6940bdcd4736e4a1f26ac34e2fc60a7305310139c1aa0ce7' 
  AND token = 'QVuMu7GVCFKIC8oGbAdANDzMfNv+za7BiCbOa72ypqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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