SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46beeb991f46c547aac1bb0a8beffd255d24afd8a35e84566beb680e3fa6ad12' 
  AND token = 'xu7kmQVrUzifR0V4zqxYdaHp8OpCXJ8TTg+kNZeDvag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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