SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '233f0b4056d911f6d0e017611066b6567d771079fa842855cf288d88c8f04c27' 
  AND token = 'LJI5CTyvIqCy2v7YOpnuHhqcr58B/DFGMAmV2X8y1wY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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