SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2453867e595a20e6aafd469e937829b9e85a4dce119bd593d107e480176cc17f' 
  AND token = 'ExVzaVXsqqkPOXSxQcsBOwMogn1xlaLt+Qyt8vVroRs=' 
  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"
    }
  }
}