SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '046730af64047276487fbd7fa2e5ae26330842d2b313c0ac5598574cc478b0d4' 
  AND token = 'yib3lFkKbMV5DoquY8bad7dRxWDUf7BaF+xrwWRFASc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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