SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e8320d5454ef943bd0ed093825e16a346a0e817fd294a55e8d77d5fefcefc9b' 
  AND token = 'FCwNjeVhqPh4YKFg1TEJC+wKQbEbBdjYAx/11dFinqU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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