SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00e7bc1beb4b80b299268f75eb7d4cb1895eb64d5785a295e331791f8db53a51' 
  AND token = 'jtjsBr0wfKVtXyTXYQ5Rwx2TgtY0SbaoAXvRQNEQlD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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