SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb39271dfa4b81f7c124b08cc81a5375ac64f03511ab607eb2716fb53df27df4' 
  AND token = 'qNMeClh63r/mHxitCR/29FV89hpfZhsggyUo2PlZZ4Y=' 
  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"
    }
  }
}