SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47e0a996ba3c503d608667796c13ab7a2a80f49bb9e173ab7507ad48311b3009' 
  AND token = 'XbxIiOfvexA1ToWFaoyRbtUWDBups6KUW+UKecLQKJ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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