SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec0515dddd4d902a913cd67c8cc981b4212da9d759fc83cf2d72040b6c34dedd' 
  AND token = 'USyR+UusaxMo8ySMVZFyJlAAtCXmUc2TlfQaWSr9Lbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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