SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d1af65483ec9c91750039838200fb1cce26acdb8446fc3dd7dae0b78156b9aa' 
  AND token = 'FsHnadfRpxJ6KYwtHiJQ8y9pFvTUelYKAXke8oR/7ic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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