SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '822832ba5f32fa740d3f02e5fbfc620385660859c07468a75c5cdf590cda8261' 
  AND token = 'SimBJ85FrocFzfqN0z3gvw4gVpr08rMNgRxYhCnXb1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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