SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b67b99e824af3884c5be30fa78c3cc5474b3adb307778877317f2cac2f6221ed' 
  AND token = 'L3FDA4uITBmPSPz8NlLm1AgLyH1MlPziM5Xq9YMXmqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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