SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02b95dd80713a66f48fe1939bd59bb31d8d7dcc43c6f4bd3b01e363dd6a8b7d1' 
  AND token = 'MqWu/Xkqd+VQEfBr66wMDIt4+2WBibZOz4KGIvQhkHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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