SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3858ee99764cda2496d25f78680bd8605667e8fde30adb4b61a3709087041bb' 
  AND token = '+SWh3dnhSL3eRiz2VBePelCS3ztVvLPTZUP/nPNG63E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}