SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c88a50f40d10fa92410ac71691a980f26f93fc8d8dc20cc469f9f4037918ca4f' 
  AND token = 'Di6pL4FStDxfzgoQvxyCLT56Q+OBSsgVCLqPSERYwFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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