SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ff21c0f94d631270d3963aae634efe960b4b91aa00a721da9b56dad8684531d' 
  AND token = 'Ttgsh06NoBSJeR4j5KNrfRRwD5u+2k9d5hRm1aP2Kuw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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