SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14a823e78286fbdc397c3f6a7b86dc76d305964e3d80338a7bab6d86a0a20727' 
  AND token = 'IOPhSGf6+ldhOVlstZGC2xiNdOGjLZDx9bxAHjqCQ/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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