SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f07da15f5e6de080d35b26330a0359ac55808f43a5bb0942557c4e191faa549' 
  AND token = 'MuzJiFNVhmuTBzDwHP3HZHpco9RYqKrH4sGV+8qzlQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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